The present application relates to storage usage in a networked computer system, and particularly to management of available room in storage.
One problem encountered in network management is the workstation whose storage becomes full. When this happens, the system will not allow the user to proceed with any process which requires additional space in storage, resulting in service calls to the system administrator and unhappy users. Additionally, software often has large storage requirements, which requires users to have large amounts of storage available. Retrofitting more storage units into an existing workstation can be prohibitively costly, particularly for a workstation which is in the last half of its life (which is often the case when a workstation user runs out of storage).
Storage architecture is one of the basic elements of computer system design, and many proposals have suggested various ways to organize and manage data storage. Some proposals have suggested a xe2x80x9cvirtualizedxe2x80x9d storage architecture, in which the client""s view of storage is separate from the physical resources that are used to implement it. One such proposal is the xe2x80x9cPetalxe2x80x9d system, described in xe2x80x9cPetal: Distributed Virtual Disksxe2x80x9d (ASPLOS 1996 paper; see also http://www.research.digital.com/SRC/articles/199701/petal.html) In this system, the user deals with virtual disks which can be created or deleted at will. The actual hardware used consists of a series of servers with nine disks connected to each. The server will use one of the disks for write-ahead capabilities, and the remaining eight to store client data.
The appearance of personal computers in the early 1980s created the need for interconnectedness among computer usersxe2x80x94to share peripheral devices, to send messages, to share data and access to computing resources. A local area network (LAN) is a network that connects users in a limited geographic area, typically within the same office, department, or building. Unlike mainframe setups, where users are limited to a host-terminal connection, LANs allow users complete interconnection with the personal computer. All devices and peripherals can be shared across a single cabling scheme. Users can connect to different servers as needed, access data or use other computer resources, or share devices that are too expensive to be used by a single user, all through the same physical connection.
The disclosed network system includes a feature which is automatically activated (unless it has been disabled) when a user""s local storage becomes full. In this case, some of the data in the local storage are written to network storage, without the user""s intervention, to free up space in the local storage. This could slow response time under some circumstances, so it is preferable to make provisions for moving portions of the data which are less used. Various algorithms may be used to define which data are used the least, and thus are to be moved to another location. The administrator may be given the option to choose to alert the user when this is happening, or to let this transaction be totally transparent and invisible to the user.
The disclosed innovations, in various embodiments, provide one or more of at least the following advantages:
allocations are transparent to the end user, so no stoppages are necessary;
system administrators are less likely to be called for lack of space;
facilitates consolidation and effective management of storage space by system administrator;
system storage may be extended without user knowledge.